Error when using latest aiohttp:
```Successfully built aiohttp asyncpg discord.py humanize uvloop ciso8601 pycares multidict yarl idna-ssl regex tzlocal websockets numpy cffi pycparser
discord-py 1.0.0a0 has requirement aiohttp<3.5.0,>=3.3.0, but you'll have aiohttp 3.5.4 which is incompatible.
```
Correction is to set version used to 3.5.0.
